Abstract:
A known compound and a new glycoside, epigeoside, were isolated from the rhizomes of
Epigynum auritum (Schneid.) Tsiang et P. T. Li (Apocynaceae). The structure of known compound was identified as daucosterol (
β-sitosterol-
β- D- glucopyranoside). The structure of epigeoside has been deduced on the basis of spectral analysis and chemical reactions as catechin-3-O-α-L-rhamnopyranosyl-( 1→4 ) -
β- D-glucopyranosyl-( 1 →6 )-
β-D-glucopyranoside.
Partial hydrolysis of Ⅱ with 0.2 mol/L HC1 afforded compound Ⅱa and rhamnose. Acid hydrolysis of Ⅱa with 2 mol/L HC1 afforded an aglycone which was identified by comparison with catechin, and glucose.